Across
- 4. The supercontinent that once was all together?
- 7. What are animals without a backbone?
- 8. Geologists further subdivide the periods of the cenozoic?
- 9. What were the first fishes to evolved and the first vertebrates?
- 11. A kind of animal that lives part of their life in the water and on land?
Down
- 1. What are animals with a backbone?
- 2. Time and the present into three long units of time?
- 3. What was the time when 95% of the animals and plants disappeared?
- 5. The first vertebrates to crawl onto land?
- 6. The era that lasted 300 million years?
- 10. Eras broken down even more?
- 12. What kind of animal is warm-blooded vertebrates who feed their young milk?